Refrigerating apparatus



Oct. 3, 1939. D. E. DASHER 2,174,623

REFRIGERATING APPARATUS Filed Jan. 29, 1957 INVENTOR. I p, pas/r52.

' ms ATTORNEYS.

Patented Oct. 3, 1939 R EFRlGERATlNG APPARATUS Don E. Dasher, Dayton,Ohio, assignor to General Motors Corporation, Dayton, Ohio, acorporation of Delaware Application January 29, 1937, Serial No. 123,032

4 Claims,

This invention relates to refrigerating apparatus and more particularlyto seals for compressors of such apparatus.

In refrigerating systems wherein a motor which 5 drives the compressorthereof is separate from the compressor it is necessary to provide aseal for that portion of the compressor shaft which extends outwardly ofthe compressor crankcase. Since the compressor shaft is ordinarilyformed of relatively soft steel, so as to permit same to be readilymachined, it is itself unsuitable for use 7 as a sealing part of thecompressor seal because the friction at such sealing point will, .aftercontinued operation of the compressor, cause Wear of and damage to theshaft thereby rendering it necessary to remove the shaft from thecompressor when the seal becomes worn and ineffective. I am aware thatothers have in some manner or another provided a hardened seal ring on acompressor shaft to eliminate wear of the shaft tothereby obviate thenecessity of removing the shaft from the compressor when the sealbecomes ineffective. Some have placed a hardened ring on a compressorshaft by temperature shrink- 5 age, after applying heat thereto, whileothers have devised various means for securing a hardened ring to ashaft, such for example, as by placing a resilientmember between thering and the shaft to prevent movement of the ring relative to the shaftto thereby insure rotation of the ring with the shaft. A certain amountof success has been derived from these prior methods of providing ahardened ring on a compressor shaft but they have not been entirelysatisfactory.

For example, if a hardened ring is sweated to the shaft by theapplication of heat thereto the shaft ofttimes warps and becomesdeformed to such a degree that it will not align properly with thebearings provided therefor in the compressor 0 crankcase. If a resilientmember is placed between the hardened ring and the shaft to secure thering to the shaft and cause rotation thereof:

therewith the resilient material of the securing member soon becomesdeteriorated by the refrig- 45 erant and lubricant contained in thecompressor and is ineffective for the purpose for which it was intended.My invention is therefore directed to overcoming the diflicultiesheretofore attendant the securing of a hardened ring, for forming asealing surface portion of a compressor seal, to a compressor shaft. Oneof the objects of my invention is to provide an improved seal for thedrive shaft of a compressor of a, refrigerating system.

55 Another object of my invention is to'provide an improved method ofapplying a hardened sealing ring to a compressor shaft.

Another object of my invention is to provide a seal for the drive shaftof a compressor of a refrigerating system which seal includes a hard; 5ened sealing member integrally secured to the compressor shaft in animproved manner.

A further object of my invention is to permanently secure one portion ofa compressor seal to the compressor shaft without application ofheat illto the shaft or to the seal portion to be secured thereto.

A still further object of my invention is to secure one portion of acompressor seal to the compressor shaft by causing one portion of theseal to 15 be integrally united with the shaft.

In carrying out the foregoing objects it is a more specific object of myinvention to secure a hardened member of a compressor seal to thecompressor shaft by electroplating a continuous go hand or collar to theshaft and to the hardened member to cause the member to be integrallyunited or permanently bonded to the shaft.

Further objects and advantages of the present invention will be apparentfrom the following 25 description, reference being had to theaccompanying drawing, wherein a preferred form of the present inventionis clearly shown.

In the drawing:

Fig. 1 is a view of a refrigerating system, partly g diagrammatic,including a compressor provided with a shaft seal embodying myinvention;

Fig. 2 is an enlarged vertical sectional view of the shaft sealdisclosed in Fig. 1; and

Fig. 3is a View showing one portion of the seal 35 in a position adaptedto be secured to a compressor shaft in accordance with my invention.

I have disclosed in Fig. 1 of the drawing a refrigerating systemprovided with a conventional reciprocating compressor I0, preferablycontain- 40 ing a refrigerant and lubricant, provided with a drive shaftII which projects outwardly of the crankcase H of the compressor toreceive a pulley (not shown) which is driven, through the medium of abelt l3, by an electric motor I separate from the compressor l0. Pistonsl5 of the compressor l0 draw evaporated refrigerant into crankcase l2and discharge the compressed refrigerant through the head portion of thecompressor to a condenser IS. The compressed re, 5 frigerant receivedin'condenser I6 is cooled and liquefied, with the aid of any suitablecooling medium, from where it flows and is collected in the receiver I1.From the receiver H the liquefled refrigerant is forwarded through asupply conduit I8 to an evaporating means or cooling element I9 shown asthe conventional float controlled flooded type. Liquid refrigerant isevaporated within the element I9 under reduced pressure, created byoperation of the compressor I0, and is returned to the compressorcrankcase through a gaseous refrigerant return conduit 2I. Operation ofthe electric motor I4 and consequently compressor ID is controlled by aswitch means 22, preferably of the snap-acting type, in accordance withthe temperature and pressure of the evaporating means I9 as isconventional in the art.

The wall of crankcase I2 of compressor II] is provided with a bearing 25which receives one end of the drive shaft I I and which is provided witha lubricant receptacle 26 for collecting a portion of the lubricantsplashed about within the crankcase of compressor I0. This receptacle 26is provided with an oil passage 21 extending to the bearing surface ofbearing 25 and a second passage 28 leading to a cavity or hollow bossportion 29 provided in the wall of the compressor crankcase I2 andsurrounding the outer end of the drive shaft I I. Within the hollow base29 there is provided a shaft seal structure generally designated by thereference character 30 and which surrounds the reduced end portion 3I ofthe compressor drive shaft II extending from a shoulder 32formedadjacent the bearing portion of the shaft.

Referring now more particularly to Fig. 2 of the v drawing it will benoted that there is a nitralloy ring 35 surrounding the reduced endportion 3| of shaft II and abutting the shoulder 32 formed on the shaft.

rotation thereof with the shaft will be hereinafter described. Ring 35has a smooth fiat end portion 35 forming a vertical sealing surfaceadapted to be engaged by an annular sealing member 31. The ring 35 andmember 31 form two sealing members of the compressor shaft sealstructure 30. The sealing member 31 is preferably formed of a specialbronze material possessing lubricating properties and which is nowconventional and wellknown to those skilled in the art. This member 31has an annular ring 38 surrounding and secured to a shoulder .portion 39formed on member 31. the inner portion of ring 38 and has its outer end43 secured to the wall of an opening provided in a plate 44. Plate I 44of the sealed structure is clamped, by a suitable clamping band 45,resilient washer 46 and bolts 41, to the end portion of the compressorcrankcase I2 adjacent the cavity or hollow boss 29. A spring 43 isinterposed between the annular ring 39 and end plate 44 to apply itscompressive force to the abutting sealing members 35 and 31 of thesealed structure 30 to hold these members in tight sealing engagementwith one another for sealing the compressor fluid tight at this point. Atubular element 49 is secured to ring 38 and extends therefrom withinand preferably in contact with the coils of spring 49 to properly alignthe spring and to also prevent vibration thereof and consequentlygeneration of noise during rotation of shaft II.

' Having enumerated the various component parts of the compressor sealstructure I will now describe the construction and method of securingthe nitra'lloy seal ring 35 to shaft II which constitutes myimprovement. The ring 35 is nitrated and hardened and has its'surfacesground fiat and I smooth. A portion of the outer annular surface of ring35 is cut away as at 5| to provide a rounded The construction of thisring 35 and the manner of attaching same to shaft I I to cause A bellowsM has its one end 42 secured to shoulder 52 thereon. This portion ofring 35 matches a corresponding but oppositely disposed similar cut-awayportion 53 forming a rounded shoulder 54 on shaft I l inwardly of theshaft from shoulder 32 provided thereon. When the nitralloy ring 35 isplaced over the reduced end portion of shaft I I and brought againstshoulder 32 on the 'shaft there is provided, by the cut-away portions 5|and 53 on ring 35 and shaft II, respectively, a groove or cavity in theannular bearing surface of ring 35 and shaft II (see Fig. 3). In orderto permanently secure the hardened nitralloy ring 35 to shaft II Iprovide a collar or band 55 (see Fig. 2) within this groove or cavity tothereby bond or unite the ring 35 to shaft I I. After ring 35 is mountedupon shaft II the shaft with the ring thereon is arranged to form thecathode in any suitable electroplating or depositing process well knownto those skilled in the art. In order to protect all surfaces of thering 35 and shaft II, from being copper plated while the same is servingas the cathode in the electrodepositing process and to insure thatcopper will be plated to the ring 35 and shaft I I only in the groove orcavity, provided by the cut-away portions 5I and 53 I protect theexposed surfaces of the ring and shaft: by covering same in any suitablemanner such as with a waxy substance or rubberized material.

shaft II which forms the bearing surface thereof fitting within bearing25. The copper band or -collar 55 integrally unites or bonds thenitralloy ring 35 to shaft I I to thereby provide an integral hardenedshoulder on shaft I I for abutment with the bronze ring portion 31 ofthe compressor seal 30. The copper band 55 in addition to bonding thehardened seal ring 35 to shaft II also forms at least a portion of theannular bearing surface of shaft I I which rotates within the crankcasebearing 25.

It will be seen that I have provided an improved shaft seal forcompressors or the like and that the one portion of the seal ispermanently secured to the compressor shaft in a novel and practicalmanner without the application of heat to thereby obviate thedifficulties heretofore enumerated. By virtue of my invention the shaft,after being machinedand properly aligned with the compressor bearings,will not be damaged or deformed upon attaching a hardened seal ringportion of the compressor seal thereto. I have thereby eliminated wastewhile atthe same time insuring alignment of shafts with compressorbearings, after the hardened seal member is secured to the shaft toafford a proper fit therebetween to thus prolong the life ofcompressors. My improved method of securing a hardened seal ring to ashaft and the location and arrangement of the sealing means as disclosedprovides a plated annular bearing surface portion of the shaft bearingwhich is rotatable within the compressor crankcase bearing.

While the form of embodiment of the invention as herein disclosed,constitutes a preferred form it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow. 1

What is claimed is as follows:

1. In a compressor having a crankcase provided with an opening in thewall thereof andhaving a rotary shaft extending through the crankcaseopening and a device for sealing the shaft fluid tight-at the opening,said device comprising a seal structure including abutting sealingmembers. one of said members being of different material than the shaftand being secured to the compressor shaft to'prevent movement thereofrelative to the shaft and for causing rotation thereof with the shaft,said securing means including metallic means integrally united with the,

compressor shaft and with said one sealing member.

2. In a compressor having a crankcase provided with an opening in thewall thereof and having a rotary shaft extending through the crankcaseopening and a device for sealing the shaft fluid tight at the opening,said device comprising a seal structure including abutting sealingmembers,.one of said members being of dif- I ferent material than'theshaft and being secured to the compressor shaft to preventmovementthereof relative to the shaft and for causing rotation thereof with theshaft, said securing means including a copper bonding element integrallyunited with the compressor shaft and with said one sealing member. a

3. In a compressor having a crankcase provided with an opening in a wallthereof and a bearing adjacent the opening and having a rotary shaftprovided with a bearing surface fitting in the crankcase bearing andprovided with a portion extending through the crankcase opening and adevice for sealing the shaft fluid tight at the opening, said devicecomprising a seal structure including abutting sealing members, oneofsaid members being of different material than the shaft and beingsecured to the compressor shaft to prevent movement thereof relative tothe shaft and for causing rotation thereof with the shaft, said securingmeans including metallic means integrally united with the compressorshaftand with said one sealing member, and said and a device for sealingthe shaft fluid tight at the opening, said device comprising a sealstructure including abutting sealing members, one of said members beingof different material than the shaft and being secured to the compressorshaft to prevent movement thereof relative to the shaft and for causingrotation thereof with the shaft, said securing means including a copperbonding element integrally united with the compressor shaft'and withsaid one sealing member,

and said copper bonding element being disposed within the shaftbearingand forming at least a portion of the bearing surface of the shaft.

DON E. DASHER.

